Concentric conductor electric cable



CONCENTRIC CONDUCTOR ELECTRIC CABLE Filed April 24, 1956 2 Sheets-Sheet 1 FIG. I

mvE/v TOR W. k. WESTON ATTORNEY Patented Sept. 7, 1937 UNITED STATES CONCENTRIC CONDUCTOR. ELECTRIC CABLE William K. Weston, Aldwych, London, England,

assignor to Western Electric Company, Incorporated, New York, New York Application April 24,

N. Y., a corporation of 1936, Serial No. 76,132

In Great Britain June 25, 1935 18 Claims.

This invention relates to concentric conductor electric cables and has for its object to provide an improved method of and machine for the commercial manufacture of such cables.

It has been proposed to manufacture concentric conductor cables wherein the inner conductor is concentrically supported with relation to the outer conductor by means of slotted washers or discs composed of an insulating material having low loss and low dielectric properties such as Ebonite, and this invention comprises a machine for the positioning of such slotted washers in spaced relationship to each other, without deformation of the central conductor and as a continuous process which can be applied to the manufacture of the complete concentric core without interruption due to this part of the manufacturing process.

According to the present invention the slotted insulating discs are applied to the central conductor continuously in spaced relation in such a manner that relative longitudinal movement be tween the discs and the central conductor is substantially eliminated during the period that the discs are forced on to the conductor.

According to a feature of the invention there is provided in an apparatus for making concentric conductor cables using slotted insulating discs, a means for giving to each insulating disc during its application to the central conductor, the same velocity as that of the central conductor advancing through the machine.

Thus in accordance with the invention the discs may be carried in a movable magazine which is given the same velocity as the conductor and from which they are fed to grip the conductor.

Another feature of the invention comprises means for holding the central conductor firmly against bending whilst the insulating discs are being applied.

The central conductor with the discs assembled thereon may be passed direct to apparatus for applying the outer conductor in a continuous process. This outer conductor may be of any desired form but is preferably flexible and may be constructed for example of a plurality of copper strips or wires suitably bound together and if desired lead sheathed, or alternatively the outer conductor may be extended in the form of a tube direct on to the central conductor assembly in which case the latter would be passed direct through a lead or other metallic extrusion press.

The various features of the invention will be better understood from the following description of one embodiment thereof which is given by way of example. In the accompanying drawings Fig. 1 shows portion of concentric conductor cable made in accordance with this invention;

Fig. 2 is a plan of the machine for assembling the discs on the conductor;

Fig. 3 is a part end elevation of the machine;

Fig. 4 is a sectional elevation on the line A-A of Fig. 2 showing the disc feed mechanism;

Fig. 5 is a fragmentary section of a modified form of magazine wheel, and

Fig. 6 is a sectional view taken on the line 66 of Fig. 5. I

The drawings are diagrammatic and show only those parts of the machine necessary for an understanding of the invention.

The insulating washers or discs 2 have slots 2' of such dimensions that when pressed into position on the central conductor l they grip the conductor firmly so as to withstand a reasonable amount of handling during subsequent operations. As shown in Fig. 1 alternate discs may be arranged with their slots diametrically opposite one another, and the outer conductor is indicated at I. It is, moreover, important that the central conductor is truly concentric to the outer conductor in the completed cable and that it is not bent during the operation of pressing the Washers into place. It is also desirable for man- 'ufacturing reasons of economy and for the quality of the completed cable that the washers be uniformly-spaced upon the central conductor and that the process of placing them in position takes place without any interruption in the passage of the central conductor through the machine. The invention provides a machine which meets the above conditions in a practical manner and which enables the washers to be applied at a rapid rate corresponding to a normal rate for the manufacture of the concentric cable as a whole.

The machine illustrated in Fig. 2 shows the conductor l passing between two rotating magazines 3, in which are out at equally spaced intervals slots 4. It is preferable that each rotating magazine 3 is of such dimensions that an even number of equally spaced slots can be out in the periphery, the circumferential spacing between the slots being equal to the desired spacing of the washers on the central conductor. The slots will be of such dimensions that one of the washers 2 can be easily slipped into each slot. Figs. 5 and 6 show an alternative arrangement of magazine according to the invention, in which alternate slots 4 in each of the, magazines 3 need only be provided, the alternate space 4 being made of material sufliciently thin to pass through the slot in the washer as shown.

The two magazines 3 are geared together by suitable means, such as indicated in Fig. 3 by the gear wheels 9, in such a way that a slot in one wheel coincides with a slot or with a thin portion of the other wheel, and so on alternately.

The washers 2 are fed through fixed magazines or feeding tubes 5 under gravity or by a spring mechanism or by other means, not shown, with the slots in the washers engaging the projection 6 which forms a guide strip on the inside of each tube 5 so as to cause the washers to tend 5 to move towards the rotating magazines. The

washers may be fed to the feeding tubes by suitable shaker mechanism of the usual type for feeding automatic machines. At the end of the feeding tube towards the rotating magazine, the m end washer is held up against a stop shoulder 8 provided by a step formed in the guide plate M of which the guide strip 6 is in effect a continuation, as is more clearly shown in the top magazine in Fig. 2, where parts of the mechanism 15 have been omitted or broken away for clearness. The trigger it which is slidably supported by an integral guide bar l l engaged in a corresponding slot formed in a guide block l5 has a' projection H (see Fig. 4) engaging with the end 20 washer, and tends, under, the action of the spring ii to push this end washer towards the rotating magazine. The trigger is restrained from moving, however, by the cam plate l3 rotatable with the magazina'until a slot in the magazine is op- 25 posite the washer. In this position the trigger is released by the cam surface N5 of the plate l3 and pushes the washer into the slot in the magazine. The continued rotation of the magazine then carries the washer towards the con- 30 ductor l, the washer being held in place by the guide plate i i. The continued rotation of the magazine with its cam plate restores the trigger to the normal position, so that another washer can occupy the position against the step 8 and 35 is then ready for the operation to be repeated. As the washer approaches the point of contact between the magazine and the central conductor it is gradually pressed on to the central conductor, until when it is on the line joining the centers of the two magazines, it is fully engaged with the central conductor. The continued rotation of the magazines and the passage of the central conductor through the machine then withdraws the washer from the magazine, leaving it attached to the central conductor as indicated in Fig. 2. It will be seen from the above description that during the process of pressing the washers on to the central conductor the central conductor itself is supported by the opposite magazine which is functioning as a backing plate. Moreover, the operation of pressing the washers on to the conductor is carried out progressively whilst the conductor is moving and there is no longitudinal relative movement between the washer and the central conductor, so that the washer is located in its final position with the minimum amount of effort and without distortion to the central conductor.

The preferred way of placing the washers on to the central conductor is to have alternate washers with the slot in diametrically opposite positions. This can be effected with the above described mechanism in which the two rotating magazines operate together, each magazine acting as the backing plate for the other, so that each magazine in turn places a washer upon the conductor. A similar pair of magazines can then, if desired, place two further washers on the conductor, spaced at half the distances between the washers placed by the first pair of magazines and so on, until the desired spacing of the washers is obtained. The second pair of washers may be located with the slots at 90 to the first pair, or any other arrangement may be made by suit- 75 ably disposingthe rotating magannes.

It will be understood that the invention is not limited to the details of construction outlined above but may be incorporated in various practical embodiments. Alsoit will be understood that the discs or Washers may be made of any suitable insulating material for example rubber compositions, ebonite, polymerized styrene, synthetic resins or the like, having low loss and low dielectric constant at high frequencies.

What is claimed is:

1. A method of manufacturing concentric conductor electric cables, which comprises applying slotted insulating discs to the central conductor continuously in spaced relation by moving the discs and conductor relatively toward each other and with substantially no relative longitudinal movement between the discs and the central conductor during the period that the discs are being forced on to the conductor.

2. A method of manufacturing concentric conductor electric cables, which comprises applying slotted insulating discs to the central conductor continuously in spaced relation by moving the discs and conductor relatively toward each other and with substantially no relative longitudinal movement between the discs and the central conductor during the period that the discs are forced on to the conductor, the said conductor being supported during the application of the discs to prevent bending of the conductor whereby the central conductor may be truly concentric with the outer tubular conductor surrounding said discs.

3. A method of manufacturing concentric conductor electric cables, which comprises applying slotted insulating discs to the central conductor continuously in spaced relation by moving the discs and conductor relatively toward each other and with substantially no relative longitudinal movement between the discs and the central conductor during the period that the discs are forced on to the conductor, arranging the slots in alternate discs in different angular positions around the conductor, supporting the said conductor during the application of the discs to prevent bending of the conductor whereby the central conductor may be truly concentric with the outer tubular conductor surrounding said discs.

4. A method of manufacturing concentric conductor cables which comprises advancing a conductor longitudinally, moving a slotted disc along with the conductor, and forcing the disc over the conductor while the two'are moving along toether.

5. A method of manufacturing concentric conductor cables which comprises advancing a conductor strand longitudinally, moving a slotted insulating disc supply along with the conductor, and forcing a disc from the supply over the conductor while the supply and the conductor are moving along together.

6. A method of manufacturing concentric conductor cables which comprises advancing a conductor strand longitudinally thereof, rotating a slotted insulating supply tangentially of the advancing conductor with a peripheral speed substantially equal to the longitudinal speed of the conductor, and forcing a disc from the supply over the conductor substantially at the point of tangency of the supply with the conductor.

7. A method of manufacturing concentric conductor cables which comprises advancing a conductor strand longitudinally thereof, rotating a slotted insulating supply tangentially of the advancing conductor with a peripheral speed substantially equal to the longitudinal speed of the conductor, and forcing a disc from the supply over the conductor substantially at the point of tangency of the supply with the conductor, the approach and departure of the supply to and from the conductor by reason of the arcuate path of the supply and the straight path of the conductor serving to force the disc over the conductor.

8. A method of manufacturing concentric conductor cables which comprises advancing a conductor strand longitudinally thereof, rotating a slotted insulating supply tangentially of the advancing conductor with a peripheral speed substantially equal to the longitudinal speed of the conductor, forcing a disc from the supply over the conductor substantially at the point of tangency of the supply with the conductor, and supporting the conductor against deformation thereof by the disc.

9. A machine for the continuous assembly of slotted discs in spaced relation on a wire particularly for the manufacture of concentric conductor cables, said machine having a disc supply magazine movable to press discs successively into engagement with the wire by reason of the relative movement between the magazine and the wire and means in the machine for longitudinally moving thewire adjacent the ,disc supply maga zine.

10. A machine for the continuous assembly of slotted discs in spaced relation on a longitudinally advancing wire, said machine having a disc carrying magazine movable to press the discs successively into engagement with the wire and movable to give to each disc during its application to the wire substantially the same velocity as that of the wire, whereby relative longitudinal movement between the disc and the wire is eliminated during the pressing operation.

11. Aniachine for the continuous assembly of slotted discs in spaced relation on a wire comprising in combination a movable disc carrying magazine movable to press the discs on to the wire, a fixed magazine for said discs, and means for transferring said discs from said fixed magazine to said movable disc carrying magazine.

12. A machine for the continuous assembly of slotted discs on a longitudinallyadvancing wire, comprising a rotatable circular disc carrying magazine positioned tangential to the wire'to force successive discs from the magazine over the wire at the point of'tangency of the magazine and wire.

' 13. A machine for the continuous assembly of slotted discs on a longitudinally advancing wire, comprising a rotatable circular disc carrying magazine positioned tangential to the wire to force successive discs from the magazine over the wire at the point of tangency of the magazine and wire, and means to guide the discs to apply the slots thereof to the wire.

14. In a machine for the continuous assembly of slotted discs in spaced relation on a wire in combination with a movable disc carrying magazine arranged to press the discs on to the wire, a rotatable circular magazine positioned tangentialv to the wire and having radial slots in the periphery thereof, a stationary magazine to supply slotted discs to the radial slots, means to transfer discs from the stationary magazine to the rotatable magazine, and means for moving the wire,

the rotatable magazine forcing discs over the wire at the point of tangency of the rotatable magazine and the wire by the relative motion of themagazine and wire.

15. In a machine for the continuous assembly of slotted discs in spaced relation on a wire in combination with a movable disc carrying magazine arranged to press the discs on to the wire, a rotatable circular magazine positioned tangential to the wire and having radial slots in the periphery thereof, a stationary magazine to supply slotted discs to the radial slots, means to transfer discs from the stationary magazine to the rotatable magazine, means to guide the slots of discs in the rotatable magazine to enclose the wire, and means for moving the wire, the rotatable magazine forcing discs over the wire at the point of tangency of the rotatable magazine and the wire by the relative motion of the magazine and wire.

16. in a machine for the continuous assembly of slotted discs in spaced relation on a wire in combination with a movable disc carrying magazine arranged to press the discs on to the wire, a rotatable circular magazine positioned tangential to the wire and havingradial slots in the periphery thereof, a stationary magazine to supply slotted discs to the radial slots, a cam on the rotating magazine coacting with a movable member on the stationary magazine to transfer discs from the stationary magazine to the rotatable magazine, and means for moving the wire, the rotatable magazine forcing discs over the wire at the point of tangency of the rotatable magazine and the wire by the relative motion of the magazine and wire.

17. in a machine for the continuous assembly of slotted discs in spaced relation on a wire in combination with movable disc carrying magazines arranged to press the discs on to the wire, a pair of rotatable magazines each positioned tangential to the wire on opposite sides thereof at the same point of the path thereof, a stationary magazine associated with each rotatable magazine to hold a supply of the slotted discs, means to transfer discs from each stationary magazine to its associated rotatable magazine, and means for moving the wire, each rotatable magazine in turn forcing discs over the wire at the point of tangency of the rotatable magazines and the wire by the relative motion of the rotatable magazine and the wire while the other rotatable magazine supports the wire against distortion by the disc being forced thereover.

18.1n a machine for the continuous assembly of slotted discs in spaced relation on a wire in combination with movable disc carrying magazines arranged to press the discs on to the wire, a pair of rotatable magazines each positioned tangential to the wire on opposite sides thereof at the same point of the path thereof, a stationary magazine associated with each rotatable magazine to hold a supply of the slotted discs, means to transfer discs from each stationary magazine to every other radial slot of its associated rotatable magazine, and means for moving the wire, each rotatable magazine in turn-forcing discs over the wire at the point of tangency of the rotatable magazines and the wire by the relative motion of the rotatable magazine and the wire while the other rotatable magazine supports the wire against distortion by the disc being forced thereover.

WILLIAM K. WESTON. 

